British Parliament was placed on lock-down after police shot an assailant, according to a British lawmaker addressing Parliament.

NEW YORK (FOX 5 NY) - Khalid Masood, who attacked Britain's Parliament, killing four people and wounding some 50, was born Adrian Russell Ajao, London's top counterterror officer said Friday.

Mark Rowley revealed the name in a briefing outside Scotland Yard in which he also announced two more "significant" arrests had been made. That brings the total number of people in custody for the Wednesday attack to nine.

"We remain keen to hear from anyone who knew Khalid Masood well, understands who his associates were and can provide us with information about places he has recently visited," Rowley said. "There might be people out there who did have concerns about Masood but did not feel comfortable for whatever reason in passing those concerns to us."

The Islamic State group said through its Aamaq news agency Thursday Masood, who plowed an SUV through at least a dozen people on a bridge in London, then drove through rails outside Parliament injuring more than a dozen along the way before stabbing a police officer was a "soldier of the Islamic State."

Masood, 52, was born in Britain and had been investigated for links to religious extremism, British Prime Minister Theresa May said in a sweeping speech to lawmakers in which she also encouraged people in London to go about their lives. At least eight people were arrested in raids, some in the central city of Birmingham.

Three people were killed in the rampage Wednesday. Police shot Masood dead.

Masood had been arrested previously for assault, possession of offensive weapons and public order offenses. His first conviction was in November 1983 for criminal damage and his last was in December 2003 for possession of a knife.

Among the killed during Wednesday's terror attack was a man from Utah who was in London with his wife celebrating their 25th wedding anniversary.

President Trump said during a brief appearance Wednesday before reporters at the White House that he was just getting the news. He called it "big news." Trump's spokesman, Sean Spicer, said the U.S. would continue to monitor the situation and update the president. Trump spoke with British Prime Minister Theresa May about the incident, Spicer said.

The U.S. Department of Homeland Security said in a statement that it "stands in solidarity" with the UK.

"With our partners in federal law enforcement, we are in close contact with our British counterparts to monitor the tragic events and to support the ongoing investigation," DHS said in the statement. "At this time our domestic security posture remains unchanged. However, our frontline officers and agents continue to stay vigilant in safeguarding the American people and our homeland."

Tourists were stranded for several hours on the London Eye, a large Ferris wheel, near the scene of the incidents.

The threat level for international terrorism in the UK was listed at severe. Wednesday was the anniversary of suicide bombings in the Brussels airport and subway that killed 32 people.